Single-phase motor.



E.' F. W ALEXANDEESONE,

I v QINGLE PHASE MOTOR. APP'LIUATIOH FILED DEC. 26, 1907.

935,881, Patented Get. 5, 19%.

Fig. 5.

MWOCWM Witnesses: I Inventor:

To all whom it may concern:

7 UNIT-Fill srairnsgaanr option,

ERNST F. W. ALEXANDERSUN, OF SCHENECTADY,-' NEW YORK, 'ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SINGLE-PHASE MOTOR.

Specification of Letters latent.

Fatented Get. 5, 1905 Application filed December 26, 1907. Serial No. 408,144.

Be it known that I, Enns'r F. W. ALEX- ANDERSON, a citizen of the United States, re-

siding at Schenectady, county of Schenectady, State of New York, have invented certain new and usefu-llm roveinents in Sin gle Phase Motors, of which the following is a specification.

My invention relates to single phase motors ofthe commutator type, and consists in an improvement in the arrangement described in my prior application, Serial No. 406,842, filed'December 17, 1907, describing a motor which is started as a repulsion inotor withits armature short-circuited; but for high-speed operation'has the exciting winding on thestator connected in the armature circuit and shunt voltage impressed on armature and exciting winding in series, and a second shunt voltage impressed on the exciting winding-felons through a rcactance.

The. nn'pose of impressing the shunt voltage on the armature circuit was to reduce the strength or" the inducing field, which field is beneficial at low speeds as regards commutation, but has an excessive and injurious effect on commutation at high speeds;

The object of including the exciting-Winding in the armature circuit was to shift the armature current somewhat out of phase with the current in the inducing winding, so as to produce a leakage field which, when out by the armature coils short-circuited by the brushes in commutation, would induce in those coils ,eleotromotive forces neutralize-- ing the electromotive force of commutation i'eactanc'e. The object of impressing the second shunt voltage'on the field winding was to, compensate for the drop in powerfactor produced by connecting the exciting winding in the armature circuit, instead of,

in circuit, with the inducing winding, and the purpose of thereactive Winding in series with the second shunt voltage was to pre vent this second shunt voltage from definitely fixing the amountand phase of the field flux and thereby making the motor essentially a shunt'motor, as would be the case were thereactive coil omitted.

My present invention consists in a novel motor construction, whereby the reactive coil. is embodied in the motor itself, so that no external apparatus is required.

My invention will best be understood by reference to the accompanying drawing, in which Figure '1 shows a portion of an end'elevastator, G Grepresentthe coils of the distributed inducing winding, which are carried 1n smaller stator slots. 1) represents coils which are carried in slots that would ordinarily be occupied by coils of the inducing winding,

but which are composed of a number of turns of comparatively small wire, instead of having, like the coils of the compensating winding, one or two turns of large wire. Thisis indicated y he cross-section of the ends of. the coils db thelelt'tdiand side of Fig.1.

Now referring to Fig. 2,1n which the co ls C and D are indlca-ted by single l1nes,the coils I) being distinguished by heavier lines, it will be seen that these coils D are so arranged that the reactive winding formed by these coils is non-inductive with respect to the other motor windings. The coils. .C, for one pole are oppositel connected with respect to the coils C of t e adjacent pole,so as to produce opposite polarities, but all the coils D are similarly connected, so that the cur- Therefore, the inductive effect of the motor windings on one coil D is offset or neutralizcd by the inductive elfect of the motor windings on the adjacent coil D, so that the reactive winding is non-inductively arranged with respect to the main motor windings. Thus, the winding formed by the coils D may be employed as the reactive winding of my former application, and its presence in the motor structure does not interfere with its own function, or with the operation of the motor.

The connections of the several windings are shown in Fig. 3, which is the same as the din rain oi? running conneciions in in i foriner umpliention, above referred to. Ti lie inducing winding l rhe exciting winding B,

and iii-nurture winding E are nll connected in series with each other. and with ihe supply l rnnsjfm'iner F.

A shunt voltage iinpr red zero 1. A FilllgiC-Pll2lSQ inc-tor ofi {he connmrinter iype havinginducing nnd exeiiing' iUiiHl on the slider and u reactive winding 7 d in ihe Hl'ilim slots indu Qly \Yiih respec" ie all Hie, other Windr s on iliQ' motor (and eonneeled in mid 'nding. i

have niei'er of (he commuii\i1l: inducing end ex he sinker, end I reactive 2 ihe Fin r said li' ilklili il ereni poie-nnnihei' z oiher n'indi" s on ihe fnz; eonneeiml io said excitiiw arranged non- Minding: h '7 (Y-lllltiFU nioior oi the commuinior nx'ii indlnxinn and l win-din ilr: 2x reiiel ow nrrai ged non-ire Lo ihe in; iioned n impressing n slinnli rig winding and said s n-1H in ihe niih res n:

r and inc-:11

, the exciting windine 1B and i zirnmtinre E in series, \i hile illiOiTllOl shunt LX'LIUUF' l l I 1 l l ing living}; included in one of said connection A. A singlephase motor of the commutnlor type lnr 'ing inducing and eiling windings on the stator, a reactive winding carried in the stator slots, sa id reactive winding being of a ,liifereiiit p0]Q-lllllflbdfffl'Olll that of the first-mentioned windings, and means for impressing a shunt voltage on said exciting winding and said reactive winding in series.

5. A singlenurse motor 01" the trier type having inducing and exciting windings on the sinker, a reactive winding enrried in the Silnim. SlOilS arranged non-indnctively with respect to the first-mentioned windings, n, i'IHDS'fOlTHIGl' for suppl ing current (0 the motion and conductors arranged to connect the exciting and :irniaiure Wind s of The motor in series and to :1V portion.

ine rrnn :rrner winding and to establish 2'1, connection from the junction of the exciting and zirznziture windings through said reactive coil. in in; intermediate point on the =trn rornier winding.

'6. A igie-plnise motor of the coniunntelordi pe having inducing and exciting windings on Lhe slaioi' e reactive Winding carried in the [nior slots ar'nnged non-hr ductivcly with 1K ect to the first-mentioned wirding a trensrormer for supplying cnrrent in the n'ioior, and conductors arranged to com' l, {he ino'for iio ihe transformer with ihe iziulik'lilg excringr and erninlure windinyg: in seriea in die order nzuned, and to e511. T ii. i cmnnzctions 'ironi hoth terminals of die exciung Winding to intermedinie poinlis on l'he transformer winding, mid reactive windwhereof, have hereunto 

